Method and apparatus for producing carbon black



c. MATLOCKA Filed Jan. 5, 19.21

ec. 10, l929.

METHOD AND APPARATUS' Fon PRODUCING CARBON BLACK Patented Deab 1o, 192eUNITED STATES PATENT OFEICEL- QHAUNOEY MAT-LOCK, OF ABROOKLYN, NEW YORK,ASSIGNOR T MONBQE-LOUISIANA CARBON COMPANY, 0F MONROE, LOUISIANA, AOOBPORATION 0F DELAWAE METHOD AND APPARATUS FOR :PRODUCING CARBON' BLACKApplication led January 5, 1921. Serial No. 435,072.

This invention relates to the production of carbon black by thedisassociation ofthe constituents of hydrocarbons and particularly tothe disassociation of a hydrocarbon gas and 5 the collection andrecovery'of the elemental carbon therefrom in the form of carbon black.

The object of ,my invention generally is to obtain a carbon black ofimproved quality from a hydrocarbon as, for example natural gas, and torecover a arger proportion of the carbon constituent per unit volume ofgas than has hitherto been possible with many known methods and devices.

A further object of my invention is a method and an apparatus forproducing carbon black whereby the cost of installation and operation ofthe plant are reduced to a minimum andthe efficiency of productiongenerally im roved, the operation, according to this met od, beingcontinuous and non-intermittent.

The method and apparatus generally used for producing carbon black on acommercial scale consists in' artially burning the natural gas or otherh rocarbon gas by means of a multiplicity o miniature burners andcausing the individual flames or products of combustion to play uponchilled surfaces whereon a portion of the carbon content ,is depositedand subsequently scraped off. .The carbon black thus obtained oftencontains metallic iron and scale, is accompanied by agglomeratedparticles of carbon and often contains other impurities andcharacteristics which render it unsuitable for certain of its uses.Moreoverthe apparatus usually employed is crude and comparativelyexpensive to build and the collecting devices wear very rapidly,

necessitating frequent periodic replacements. Further the usualcommercial plants are cumbersome and occupy large areas.

Certain other methods have been suogested for the manufacture of carbonblac but none of them appear to have reached the practical or commercialstage of development.

`Accordin to my improvements I produce a carbon b ack of an improvedcharacter which is peculiarly free fromy the above mentioned injuriousconstituents and undesirpartial combustion.

able characteristics, and moreover, I obtain larger quantities of carbonperunit lvolume of gas and in a more etlicient and less expensive mannerthan yis possible with known methods and devices. Generally stated, myimprovements reside in the continuous artial or incomplete combustion of.the hy rocarbon gas (preferably at substantially atmospheric pressure),in a comparativelylarge furnace by supplying to the f urnace and tothegaseous flame predetermined' quantities of preheated air which areinsufficient for complete combustion, the adjustments Ipreferably beingsuch that the resulting products of combustion and unburned gases aremore or less confined in the furnace and raised to athigh tem erature byheat energy .from the partial com ustion takingi'lace and the subJectionof the resultant pro ucts to a carbon isolating process. The, gassupplied may also be preheated in certain cases instead of preheatingthe air, or both the gas and air may be given the required amount ofheat energy prior to the In accordance with certain other applicationsfiled on even date herewith, I may employ aprecooling system and afiltration or precipitation separation system for collectin the carbonafter it is disassociated. A

n the practice of my invention I have devised a comparatively largefurnace with a battery of'large burners or gas intakes with their mouthsopening into the furnace at points a shortdistance from the bottom ofthe furnace, and with an air intake or intakes disposed slightly belowthe level of the burnproduce complete combustion, the gas being suppliedata pressure slightly above atmosl pheric and the burning taking placeat substantially atmospheric pressure. Preferably means are rovided forregulating the pressure and t e volume of 4the gas supplied to theburners and for ad'usting the quantity of air furnished to the urnace.The resulting productsof combustion and unburned "ume, and thence gasesare' more or less conned o r trappedy in the furnace and the temperaturethereof ele' vated to thedesired oint for best operation. Provisionis'made or the gradualv exhaust of the resulting products and gasesthrough a restricted outlet near the top of the furnace. The hotproducts with the liberated carbon black are conductedfrom this outletthrough. a cooling system or circuit of restricted dimensions forreducing the temperature, increasing the density and reducingjthe voltoa collector where the carbon black is separated from the otherconstituents. The collector is preferably either of the electricalprecipitation type Yorvof the closed bag filtration type. A fan orblower together With-an exhaust regulator is' provided for the purposeof assisting to maintain the natural draft of the products of combustionand to impart thereto the required velocity through the restrictedpassages of the cooling system, as I find that the efliciency .fofoperation and production is` thereby increased. The hot gases with theliberated carbon in suspension are drawn through the conduitsatsufficient velocity to carry along therewith the greater portion of anyocculent carbon which may be precipitated in the cooling pipes, andsubstantially the` whole of the liberated carbon black which leaves thefurnace with the vgases is borne to the collector and there recovered.

The advantages of my improved method and apparatus for producing'carbonblack will more fully appear. from the f following detailed 'descriptionand the accompanying drawings, the latter being a, diagrammaticlillustration of the system and apparatus. Fi 1`is a diagrammaticillustration of one em odiment of my improved method and apparatus andFig. 2 is a diagrammatic illustration of a modified collector.

Referring to these drawings I have illustrated in section `a furnace 1,this furnacebeing of large or generous dimensions as comparedwithcertainof theother elements of the apparatus. There are provided a number ofburners 2 (only two being illustrated), which are supplied with ahydrocarbon gas, for example natural gas, through a supply pipe 3leading to a gas main 4. A valve 5 is lndicated for controlling the gascircuit and preferablythe circuit is provided with a gas 'pressureregulator (not illustrated) for the pur ose of supplyinggas at asubstantially uni orm and constant pressure. The furnace is preferablysealed against the entrance of air or `other oxygen containing lagentexcept through an air opening 6. rllhe air is supplied through a pipe 7which passes through a he ating chamber 8 for the purpose of preheatingthe air to the required temperature before it enters the furnace. Theheating means may be steam which is admitted through pipe 9. A regulator10 may be provided for adjusting i area to give the'exact quantity ofair from the other gases.

as o the amper type by which means the air passage may be adjusted tothe recuired preferably at atmospheric pressure)- desired. It

- is noted that the burners 2 are disposed near the bottom of thefurnace' and that the air opening 6 is disposed slightly below the levelof these burners, this arrangement having been found to give goodresults. It is under stood, however, that this arrangement may be variedwithin certain limits, without departing from the spirit of theinvention.

Near the top of the furnace 1 there is plovided a restricted outlet 11which leads to a 'cooling circuit or' system 12. From the cooling system12 the furnace outlet leads through a heater 13 and from thence to acollector 14. The cooling system consists of a pipe of restricteddimensions as compared to the volume of the furnace and a water spraysystem 15 which may continuously spray cold water upon the cooling pipes12 for the purposey of reducing the temperature of the products ofcombustion passing therethrough. vThe de' gree of cooling may beregulated by adjusting the supply of water to the spraying system as forinstance bymeans of a valve 16 in the water main. The cooling pipes 12are observed to slightly diminish in cross section from the front of therearmost end. This reduction in cross section may be madebecause theproducts of combustion may be reduced in volumeas increase in density ofthe gases passing through the cooling and collector system promotes theeicient separation Two different ,types of collectors are illustrated,collector 14 being of the bag filtration type and collector 14 being ofthe electrical precipitation type. The collector 14 consists generallyof a container, preferably of cylindrical shape, withv the hopper 17 onthe lower part fo'r collecting the carbon black as it falls by. gravityor is caused to fall from the filtration cated diagrammatically at 18whose open ends register with the openings 19 in the par-l tition plate20 carried b l the container. The bags (only two of whic are shown) maybe carried in an suitable manner vand means `ma be provi ed, if desired,for agitating or sha (ing the bags to loosen the carbon black collectedthereby. I have illustrated a novel bags. The filtration bags are indi-4they are cooled. The resulting of the carbon n chain arrangement forloosening the carbon.

black, a chain 21 being suspended from the bar 22 and the whole beingmounted upon a crank 23 whereby the chains maybe given the necessarymovement for contacting with and agitating the bags. The chainsreferably are suspended to hang downwar ly within the bags. v

A blower or exhauster24 is provided .for assisting the natural draft ofthe system,

" anche Y' the blower beingv connectedwithvtheupper mosphere), theburners are lighted and the air regulator 10 is adjusted to'give theexactquantity of preheatedv air. desired for the most etlicientoperation of the system andthe products of combustion resulting 4fromthe f incomplete combustion of the ,natural gas gradually accumulate inthe furnace until the 'upper part thereofy is completely filled l withthe gases and the liberated carbon black in suspension. The main gate 27in the circuit being open the products of combustion with the suspendedliberated carbon black begin to circulate through the coolingsystem, 12and the blower 24 together with its regulating valve 26 are adjustedtogive an exhaust pressure and velocity sufficient to carry the productsof combustion to ether with the suspended carbon through t e reaftpressure may be regulated or eures in the furnace off14eo F. te. 180ocareful adjustment of the air a mitted into the furnace, both theyieldand quality of carbon black produced 'are ood. A test of the gasesnear the top of the urnace with one adjustment vshowed a total absenceof free ler'centage. (1.8%)" of carf oxygen, ar small bon monoxide (Canda lar er percentage (7.7%) of carbon ioxide (C52). Good results wereVobtained with adjustments-giving v other percenta es of these gases`Itwillybe apparent that' y preheating the gas'anjdair the resultingburnin mixture may "be raised bythe combustion o a small portion of thehydrocarbons, to a temperature suiicientf-to decompose or dissociate the-rer'l'iaining hydrocarbons. This temperature may be 0btained-uniformlythroughout the massdof burnin gases without disturbance through the' coo'ng effect of chilling plates or other heat abstractin objects. It isalso observed that ywith an a' justment suchthatthe products ofcombust1on and intermixed gases are `all retained above the levelxof'the burners 2,

the yield and qualityare good. lFor-exainple,

. (as measured by pyrometer 30 and with as indicated in Figure 1, thereseemsv under certain conditions to be a clear and defined strictedcooling system and through the iltration bags 18 of the collector. Thevelocity in the Acooling circuit is -such that the greater .portion ofocculeht carbon which is precipitated or becomes deposited upon theinnerwalls of the cooling circuit is carried along with the main stream ofproducts of combustion into the collector so that thegreater portion ofthe liberated carbon black which `leaves the furnace through the outlet11 aetually reaches the collector and is there tiltered out yanddeposited into the hopper 17, the cleansed gases pass out through aconduit 25 and the blower 24.

I have found that the bag collectors operate very efficiently to filterout the liberated carbon black and that they work particularly `well attemperatures below 225 F. Eiiicient dividing vline or blanket 31 betweenthe gases 82 above and the air below this line, and the air nterin thefurnace and' collecting beneath this lanket is probably preheatedA bythe heat from the partlal combustion to a certain degree before itenters the combustion Ispace. -This heat energy is accumulative of theheat energy addedftotfthe' air *in the heater 8.

I may also preheat the 'gas before it enters a the. furnace in somecases. For example I provide a heating chamber 33 through which `passesthe gas supply pipe 3. The heatin results for instance have beenobtained with the operation of the collector gases at a temperature of`170 F. to 225"- F. found that with thel proper adjustment of the gasand air supplied to the furnace and with a proper balance of the systemincluding the careful adjustment of the exhaust pressure and the degreeof cooling that the carbon black recovered in the hop er 17 is aparticularly desirable commercia product and is free from the abovenoted injurious constituents and undesirable qualities; moreover, theyield of carbon blackper unit of gas is found to be vgreater than theyield of 'carbon black produced by many known methods and devices. j

These results are noticeable to a certain degree under variousconditions of operation, but are particularly marked with tempera- Ihave also bon constituent separable when burned in agent may pipe 34. t

For the purpose of relieving the furnace 1 of the products ofcombustionor for' other reasons an outlet 282 is provided and isdisposednear the top of the furnace, a door 29 being positioned-upon theupper end of the pipe 28 for the purpose of opening or closing` thesame. The heater 13 is in the. nature of a steam chamber for preheatin.the cooled products of combustion before t ey enter the collectors.While I have indicated in the process as hereinabove detailed thatnatural hydrocarbon `gases may be employed, it is,

erated hydrocarbon gases, the essentialre-` quirement being that thegases `contain-a caran atmosphere deprived largely of oxygen...

It is obvious, also, that while as in the 'cas'e 4.

of a natural gas,l atrue gas'non-condensible at ordinary temperaturesand pressuresvgis employed, condensible gases .o'r vaporscn tainingcarbon constituents .-'be steam admtted throug 12;) 'of course, possibleto employ artiically geni these vapors with hydrocarbons may also beemployed.k

In accordance with the requirements of the .patent statutes I have setforth only one form .dia rammatic for convenience 1n illustration,

cient for complete combustion;

an it is understood thatl the .claims annexed hereto are not to beconstrued as limited to the exact methods anddevices illustrated,

except as is specifically recited therein, but are to be construed tocover all modifications coming within the spirit of the invention.

I claim;

1. The method of separatin and. recovering carbon black from a hyrocarbon gas which comprises partially burning the gas by supplyingthereto a regulated quantity of preheated air.

2. The method of separatin and recovering carbon black from a hyrocarbon lgaswhich consists first, in preheating the gas; second,`preheating to the 'desired tem erature a quantity of air and third,partially urning the preheated gas by the sup ly of said preheated airin quantities insu cient for complete,l combustion.

3. The method of separating and recovering carbon black from ahydrocarbon gas" consisting first, in preheating the gas; second gas,the combination of a furnace adapted to receive and burn'the gas out ofcontact with heat abstractin surfaces, means for supplying gas to theurnace, means for preheating the gas before it reaches the furnace, anair supply means for furnishing air in quantities insuicient forcomplete combustion, means for reheating the air before it is suppliedto t e furnace, and a collectin s stem for separating the liberatedcarbon b aeg from the resultant products and gases.

8.-4 A process of producing carbon black which comprises heating ahydrocarbon gas and air, burning a mixture of said heated drocarbon gasand air in quantity insullicient to completely oxidize said h drocarbonsand recovering the carbon black t ereby produced.

9. A process of producing carbon black which comprises heatinghydrocarbon gas, heating air, oxidizing said hydrocarbons with asulcient amount of said heated air to bring said hydrocarbons to adissociatin temperature while avoiding a complete oxi ization of saidhydrocarbons and thereafter cooling and separating carbon. black fromthe gaseous products thereby produced. v

In testimony whereof, I aflix my signature. CHAUNCEY MATLOCK.

partially burning said prehead gas by the l supply of preheated air inquantities lnsuithird cooling the resultant products and fourth,subjecting the cooled gases to a carbon isolating process.

4. IThe-*method of separatin and recovering carbon black from a hydrocaron gas consisting first, in partially burning the` gas by the supplythereto of preheated air in quantities' insuicient for completecombustion; second, compressin and cooling the products of ycombustionan third, subjecting the cooled products to a carbon isolating process.

5. The method of separating carbon black from a h drocarbon gasconslsting first, of partially urning the gas by supplying theretopreheated air in quantles insuilicient for complete combustion whilepermitting the products of combustion to retain the heat evolved duringcombustion and second, cooling the aforesaid gases and subjecting thecooled gases to` a carbon black isolating process.

6. The method of se arating and recovering .carbon black from aydrocarbon gas whic f 7. VIn an apparatus for separating and re-

